Sources say Nicole Alvarez will be asked questions that she declined to answer for police investigating Dr. Conrad Murray in a manslaughter probe related to the singer's death.

Prosecutors investigating Michael Jackson's death have called the girlfriend of the singer's personal doctor to testify before a grand jury today, according to the woman's lawyer and sources familiar with the matter.

The Los Angeles County district attorney's office is asking the grand jury only to take testimony from Nicole Alvarez and that the panel is not being asked "at this time" to determine whether Dr. Conrad Murray should be charged with a crime, the sources said.

Murray has been identified in court papers as the target of a manslaughter probe related to Jackson's death, and the sources told The Times that his girlfriend, a 27-year-old actress, has not been cooperating with detectives.

The prosecutors are using the grand jury's subpoena power to ask Alvarez questions that she declined to answer for police, according to the sources, who spoke on the condition that they not be named because the investigation is ongoing.

Alvarez's attorney said his client received a subpoena several days ago to appear before the grand jury this morning.

"We are definitely going to cooperate, but as to whether that happens tomorrow -- it's short notice -- that remains to be seen," lawyer Joseph Low IV of Long Beach said on Tuesday.

This summer, police searched the apartment where Alvarez lives with the couple's infant son, but she was not forthcoming with detectives, the sources said.

Low disputed the characterization of Alvarez as uncooperative.

"The only thing she asked was that she be notified when they wanted to talk to her and that she have the ability to have a lawyer there because she doesn't know what to expect," Low said. He said detectives arrived unannounced to search her residence and take a statement.

Low said he would be "surprised" if Alvarez knew anything useful to investigators.

A spokeswoman for the district attorney's office, Jane Robison, said: "We cannot comment on whether there is or is not a grand jury proceeding."

Murray acknowledged to detectives that he administered the anesthetic propofol and other medications to Jackson before the pop star's death June 25.

The Los Angeles County coroner's office determined that Jackson died from "acute propofol intoxication" combined with sedatives, and labeled his death a homicide.